1. Imagine that you work at a company that prepares chemical solutions. You are asked to label a solution to sell to different customers. One customer is a hospital, another is a chemistry lab at a university, and a third is a physics lab at a university. You added 900 kg of NaCl in a 100-liter container and filled it with water to a volume of 100 liters. Assume standard (STP) conditions.

Determine the following:

• Mass percentage of the solution for the customer in the hospital
• Molarity for the customer in the chemistry lab
• Molality for the customer of the physics lab

a.

%w/w = (grams solute/g solution)*100
% = [900,000/(100,000+900,000)] x 100 = ?

b.
M = mols solution/L solution.
mols solute = grams/molar mass = ?
L solution = 100
Solve

c.
m = mols solution/kg solvent
m = mols solute same as for part b.
kg solvent you don't know and there is no way to calculate it. You don't know how much water was added to the 100 liter flask; you know only that enough water was added to make 100 L along with the 900 kg NaCl. What to do? Put a note in the sample sent to the physics lab to take it to the chemistry lab and have it analyzed.

To determine the mass percentage of the solution for the customer in the hospital, molarity for the customer in the chemistry lab, and molality for the customer of the physics lab, we need to calculate the mass of NaCl, molarity, and molality.

1. Mass percentage of the solution for the customer in the hospital:
To calculate the mass percentage, we need to find the mass of NaCl in the solution and divide it by the total mass of the solution, then multiply by 100.

Mass of NaCl = 900 kg
Total mass of the solution = 100 liters (assumed to be equal to 100 kg because 1 liter of water has a mass of 1 kg)

Mass percentage = (mass of NaCl / total mass of the solution) x 100
= (900 kg / 100 kg) x 100
= 900%

The mass percentage of the solution for the customer in the hospital is 900%.

2. Molarity for the customer in the chemistry lab:
Molarity is defined as the number of moles of solute (NaCl) per liter of solution. To calculate the molarity, we need to find the number of moles of NaCl and divide it by the volume of the solution in liters.

Number of moles of NaCl can be calculated using the formula:
moles = mass / molar mass

Mass of NaCl = 900 kg
Molar mass of NaCl = molar mass of Na (22.99 g/mol) + molar mass of Cl (35.45 g/mol) = 58.44 g/mol

Converting the mass of NaCl from kg to g:
Mass of NaCl = 900 kg x 1000 g/kg = 900,000 g

Number of moles of NaCl = 900,000 g / 58.44 g/mol = 15,401.2 mol

Now, let's calculate the molarity:
Molarity = moles of NaCl / volume of the solution (in liters)
= 15,401.2 mol / 100 liters
= 154.012 mol/L

The molarity for the customer in the chemistry lab is 154.012 mol/L.

3. Molality for the customer of the physics lab:
Molality is defined as the number of moles of solute (NaCl) per kilogram of solvent (water). To calculate the molality, we need to find the number of moles of NaCl and divide it by the mass of water in kilograms.

Number of moles of NaCl remains the same as calculated previously:
Number of moles of NaCl = 15,401.2 mol

Mass of water = 100 liters (assumed to be equal to 100 kg as mentioned earlier)

Now, let's calculate the molality:
Molality = moles of NaCl / mass of water (in kg)
= 15,401.2 mol / 100 kg
= 154.012 mol/kg

The molality for the customer of the physics lab is 154.012 mol/kg.

In summary:
- The mass percentage of the solution for the customer in the hospital is 900%.
- The molarity for the customer in the chemistry lab is 154.012 mol/L.
- The molality for the customer of the physics lab is 154.012 mol/kg.